Jack Burns (PI), Gregg Hallinan (co-PI) Judd Bowman, Bob MacDowall, Justin Kasper, Richard Bradley and Marin Anderson
E-mail: [email protected]
FARSIDE
The Space Astrophysics Landscape for the 2020s and Beyond
The Dark Agesand Cosmic Dawn
Magnetospheres and Space Environments of
Habitable Planets
Simulation: Marcelo Alvarez
Young Mars was warmer and wetter
Mars atmosphere removed by coronal mass ejections from the young Sun (Jakosky et al. 2015)
- Flares – higher X-ray and ultraviolet radiation flux –> heating results in extended thermospheres (Lammer et al. 2003)
- Coronal mass ejections (CMEs) – higher stellar wind flux –> can erode atmosphere – eg. ion pick-up erosion (Kulikov 2007)
Magnetic activity can redefine habitability!
The M Dwarf Opportunity
Rocky planets are particularly frequent around M dwarfs (Dressing & Charbonneau 2013, 2015)
The nearest “habitable” planet likely orbits an M dwarf within a few pc
Credit: Chuck Carter / Caltech
Low Frequency Radio Emission
Auroral radio emissionmeasures magnetic fields
Type II radio bursts traces density at CME shock
Paradigm Shift
Gallagher & D’Angelo 1981
Requirements
Need
Need many km2 of collecting area…
in space…
that can monitor 1000s of stellar systems simultaneously
EASY!
Credit: Steve Bartlett
The Lunar Far-side
Sensitivity of a dipole ∝ collecting area / system temperature
∝ λ2 ∝ λ-2.6
Credit: Andres Romero-Wolf
Jim Bridenstine: “we’ll be putting pieces of wire on the moon”
A dipole of a few meters length on the moon has a collecting area of ~0.3 km2 at 300 kHz
A dipole at 300 kHz is 20x more sensitive than at 30 MHz
Plasma Noise
RAE-2 occultation of Earth in 1972
Radio-frequency Environment of the Lunar Far-side
FARSIDE Probe Study
- Science Drivers: The Magnetospheres and Space Environments of Candidate Habitable ExoplanetsThe Dark Ages and our Cosmic Dawn
- Assumptions:i) Lunar Gateway in operation (available as a communication relay)ii) $1 billion cost cap and 500 kg mass cap [for deployed hardware]
- Timeline:Nov 2018: Directed probe study commencedMar 2019: Overall architecture selected [Team X]Apr 2019: Follow up mission and instrument studies plannedJun 2019: Initial report completedSep 2019: Engineering Concept Definition Package
Sun Radio Interferometer Space Experiment (SunRISE)
Loose formation of six 6U form factor smallsats in 10 km sphere
Radio receiver (0.1 – 20 MHz) with crossed 5 m dipole antennas
Currently in Extended Phase A Study
Courtesy of Justin Kasper & Joe Lazio
The OVRO-LWA
FARSIDE Antenna Node
Simple receiver architecture
Rad tolerant flight proven Low Noise Amplifier (LNA)
Night time: radioisotope heat unit (RHU)
Power: 0.5 W per node
Mass: < 1 kg per node
50 dB Gain
Laser module
Optical fiber
50 dB Gain
Laser module
Optical fiber
Shielded Box
10
km
Power: 2 x EMMRTGs
Base StationCorrelator
PowerTelecom
Command and Data Handling
128 antennas total
Arranged in a “petal” configuration
16 antennas per spoke (20 kg)
Rover covers <50 km in one single lunar day
Science Data
Frequency range: 0 – 25 MHz (1400 channels)Integration time: 60 s
All visibilities: 65 GB/dayAll-sky imaging every 60 seconds (Stokes I and V)
Deep all-sky imaging every lunar day
Monitors ~4,000 stellar/planetary systems out to 25 pc
OVRO-LWA - 25-85 MHz, 10-second integrations Anderson et al. 2018
Kao et al. 2018
Krupar & Szabo (2018)
Solar-like Type II and Type III Events out to 10 pc
Burkhart & Loeb 2017
Proxima b
Constraints on the Magnetic Fields of the Nearest Habitable Planets
FARSIDE @ 300 kHz1σ in 1 hour: 100 mJy
FARSIDE @ 300 kHz1σ in 1 lunar night: 5 mJy
Comparative Planetology
JWST
HabEx
TMT
Additional Science
- First constraints on Dark Ages 21-cm power spectrum (ruling out exotic models)
- Heliophysics: [poster of Bob MacDowall]
- Monitoring of auroral processes and lightning at Jupiter, Saturn, Uranus and Neptune
- Searches for unknown large magnetized bodies in our solar system (e.g. Planet 9)
- Tomography of the ISM
- SETI
- Serendipitous!
All gas giants and Earth have strong auroral radio emission
Electron cyclotron maser emission – coherent, highly circularly polarized
= BGauss x 2.8
From space From the ground
Adapted from Zarka (2007)
No direct evidence of CMEs on any star other than the Sun to date
Magnetic field configuration may be play an important role (Alvarado-Gómez et al. 2018)
M d
warf Su
pe
rflares
Donati et al. 2006
Adapted from Aarnio et al. 2012
Stellar CMEs